Refrigeration



June 5, 1928.

A. Ll-:NNING REPRIGBRATQION Filed Jan. .22, 1927 Patented; J une 5, 1928.`

UNITED .STATES PATENT oFFlca.

.ALVAB LENNING, OF BROOKLYN, NEW YORK, A SSIGNOR TO ELECTROLUX SEB'VEL CORPORATION, F NEW YORK, N. Y., A CORPORATION OF DELAWARE.

BEFBIGEBATION.

p Application led January, 1927, Serial N o. 162,921, and in`Germany July 31, 1926.

My invention relates to the art of refrigeration through the agency of absorption, heating and cooling. I contemplate various improvements upon existing devices which operate to give higher efficiency and simplified construction. A

I have found that there is some diiliculty in.starting a unit of the constant pressure absorption type or one in which no' appreciable pressure differences are available 'and wherein the refrigerant,- pure or d'lute, passes through V" small conduits or pipes. This is particularly true of the 'refrigerant conduit connecting .the condenser with the evaporator of a constant pressure system where this conduit passes from the condenser downwardly and vthrough a heat exchanger and then upwardly to the evaporator. I have found that increase of diameter of pipes to facilitate starting is 'not generally desirable. I ,have found that the diiiiculty of starting in such an instance, which is due to capillary resistance, can be overcome by using a wick, preferably consisting of a metal wire or a series ofl metal wires running all' the way through the liquid conduit. It is accordingly one object of the present invention `to provide a'system wherein starting is made easy and quick and wherein the capillary resistance to startingl is overcome by means of the .provision of a wick which serves to induce Yflow of liquid through the conduit.

I have further foundthat an improved f apparatus is obtained by using a contlnuous conduit as a cooling element for such parts as the absorber. By using a pipe of relatively small diameter, the velocity of water or other cooling liquid is made much higher than in an ordinary cooling jacket, thus producing improved heat transfer. Such a coil is preferably made of copper or other noncorroding metal which e minatesthe rusting which is `liable to occur in the jacket i5 ordinarily used in connection with an iron or steel vessel. I further improve such apparatus by thermally connecting the co`l with the absorber by soldering or dipping in tin or by means of an aluminum casting surrounding the convolutions of the coil. Such a' coil arrangement may be used with -of the generator.

refrigerant flowing from the evaporator into .this Tower vessel evaporates around the refrigerant cond-uit, whereby all refrigerant is uti lized and the recooling of the refrigerant before entering the evaporator is intensified.

It is ymy object, further, to simplify .the construction of apparatus arranged to precool absorption liquid before entering the absorber. In order to obtain high efficiency of absorption liquid precooling with simpliied construction, I use the above mentioned coil surrounding the absorber and contact the absorption liquid conduit leading tothe absorber with a plurality of points on different convolutions ofthe coil. Thel contact points are soldered or otherwise fusbly connected in order to obtain good 30 heat transfer.

I propose further to enhance the rate of v heat transfer between cooling water and weak absorption liquid and to this end I insert-in theY absorption liquid line a core g5 which increases the velocit-y of liquid.

In order tosecure good heat transfer in gas heated absorption refrigerators, I utilize a generator with a central flue and place an extended core within the flue 'which 90 forms a. narrow annular passagewayl for combustion gases in contact with the metal This reduces the thickness of the gas layer'through which the heat has to pass.

With the above and other objects in view, I have hereinafter described preferred means for carrying out the objectsin the form of description of apparatus illustrated on the accompanying drawing of which Fig. 1 is a more or less diagrammatic drawing, in Sectional-elevation views, of ank apparatus embodying my invention but amply clear to enable vone skilled in the art to which the invention relates to make, construct and use the same;

Fig. 2 is a cross section of a conduit y shown in Fig. 1; and

chamber 11 may be considered the main gencrator and the structure makinr up chamber 12 may be considered an auxiliary genera-V tor. Chamber 12 communicates with chamber 11 through a conduit 14 which is iliade and arranged so as to form the upwardly extendingv vapor and liquid pipe of a thermo-siphon. A flue 15 p-asses centrally through generator 10. A suitable'source of heat, as for instance, the gas burner 16, is placedu in the bottom of ilue 15 and an extended, generally cylindrical baiie 17 within fiue 15 serves to decrease the thickness of the hot gas layer therein while at the lsame time increasing the velocity ofthe hot gases therethrough which increases the rate of heat transfer from the hot gases to the generator.

A conduit 18 connects the top of chamber 11 with the inner space of rectifier-condenser 19 and serves to convey vapor from the generator to the rectifier-condenser. Member 19 constitutes both a rectifier and a condenser. Rectifier-condenser 19 is cylindrical and is tilted from the horizontal as shown and lconduit 18 runs upwardly along the bottom thereof. Rectifier-condenser 19 is partially surrounded by cooling water jacket 20. From the lowest point 1n rectifier-condenser 19, which is within a well 8, a conduit 21 passes downwardly through conduit 23, horizontally through heat lexchanger 24 and upwardly through conduit 25 to the upper art of evaporator 26 which is situated with- 1n the space 9 to be cooled. A fine wire constituting a wick 22 is placed within conduit -21 throughout its .entire length. Within evaporator-26 is a -series of disks 27. Disks 27 are Vformed with holes surrounded by raised rims 29. Holes in adjacent disks are preferably staggered relative to each other.

A conduit 30 connects the bottom of evaporator 26 with space 31 formed between tube heads 32 and 33 and around tubes 40 within heat exchanger 24. A conduit 35 connects space 31 with the/lower part of absorber 36.

' Absorber 36 is supplied withdisks 37 which may be similar in form to disks 27 within evaporator 26. A conduit-23 connects'the top of absorber 36 with space or end chamber 39 formed between tube head 32 and the adjacent end of heat exchanger 24. Tubes 40 connect space 39 with space 41 Ewhich lat-.

43 is provided on the under side of conduit 21 where it passes above the upper end of conduit 35.

A cooling coil 44 passes around and is welded or soldered or connected by lmeans of any other fused metal connection to the outside of absorber 36. Cooling water is introduced through conduit 45 into coil 44 and is discharged through. conduit 46 to water jacket 20 and is finally discharged through conduit 47. A conduit 48 leads from the bottom of absorber 36 to a filling plug 49. A conduit 50 leads from .conduit 48 to heat exchanger 51. A conduit 52 leads from heat exchanger 51 to the upperpart-of chamber 12 in generator 10. A conduit 53 leads from the lower'part of chamber 11, through heat exchanger 51 (Figs. 2 and 3) is placed and supported by a number of arms 55. The purpose of rod 54 isv tov increase the velocity of the liquid within that portion of conduit 53 and thereby increase the rate of heat transfer between this liquid and the cooling A gas .ventilation conduitl 56 connects condenser 19 with space 31 within heat exchanger 24.

Water, in coil 44.

The operation ofthe apparatus is as follows: d

, -Chamber 11 of generator 10 contains a solution which consists of y a refrigerant, for instance ammonia, dissolved in an absorbing medium, for instance water. Application of heat froingas burner 16 drivesthe ammonia `out of solution and it passes in vaporous form upwardly through conduit 18. Any

water vapor that may be entrained with the ammonia vapor iscondensed in thatportion of conduit 118 which lies within rectifiercondenser19 and runs back to chamberll. The dry gaseousammonia passes out'of conduit 18 inIrectiier-condenser 19 and is here condensed to va liquid by the cooling action of thewaterjacket 20. ATl ondensedamlInonia being cooler than superheated boiling point of ammonia, the water vapor in conduit 18l is condensed by liquid ammonia in the rectifier-condenser surrounding conduit 18 while itis impossible'with this arrangement to have condensation of ammonia in conduit 18 since the heat transfer from the vapor in conduit 18 to the liquid ammonia surrounding conduit 18 cannot continue to such degree of equalization that" equal temperatures are obtalned. A small quantity of hydrogen may pass from absorber 36 throughgenerator 10 to rectifiercondenser 19 where it Wouldftend to collect as it is non-condensable at temperatures which prevail in the rectifier-condenser. To prevent the possibility of the formation of a gas pocket inrectiier-condenser 19, conduit 56 is provided which allows the passage of gas from rectifier-condenser 19 to space 31 in heat exchanger' 24. The liquid ain-I monia passes 'from rectifier-condenser 19 through conduit 21 in which is located the wick consisting of a metal Wire 22; The

. per part of evaporator 26.

purpose of wick 22 is to reduce the capillary resistance to flow in conduit 21, especially when the 'apparatus is' first started after an idle period. lVick' 22 operates to quickly carry liquid ammonia from the rectifiercondenser to the evaporator. The liquid ammonia passes from conduit 22 into the up- Rectifier-con- A denser 19 is situated at such a distance above 31 throughA conduit 35 to the evaporator that the liquid ammonia flows into the evaporator by gravity. A gas inert with respect to ammnia, for instance hydrogen, is introduced into the top of evapl orator 26 through conduit A25. Refrigeration in evaporator 26 is produced as a result of the diffusion of the ammonia into the hydrogen. vThis diffusion is aided by disks y 27 which are so constructed as to retain` liquid ammonia in shallow pools thereon until it diffuses. As ammonia has a greater specific weight than hydrogen, va mixture o ammonia and hydrogen has a greater specicweight than pure hydrogen. For this reason, and due to thearrangement of ap' the gaseous ammonia-hydrogen l paratus, mixture formed in the evaporator will pass downwardly through the holes '28 in disks 27 within evaporator 26 andA out through conduit 30 to space 31 in heat exchanger 24. Here lit is in heat exchange relation with liquid ammonia in conduit 21 and with hydrogen in conduits and absorbs heat from both of these substances. The mixture of ammonia and hydrogen passes outof space l the lower part of' absorber 36. Within 'absorber 36 the mixture comes in contact with water which passes downwardly over disks 37.

conduit 23 to space fsince the cooling fluidin the tively'high velocity A'Ihe wa! se'ctional area vof a pipey formed yas a ter absorbs the ammonia gas v'and heat is generated. This heat is absorbed by the cooling Water in coil 44. The hydrogen is not absorbed and as it is lighter than the ammonia-hydrogen mixture it passes p upwardly through absorber 36 and through 39 in heat exchanger 24. Any liquid that is vcarried into space 39 will collect in the bottom thereof and ass through capillary hole 42 in head 32. ro-

jection 43 on conduit 21 above'the opening 'of conduit 35 serves to prevent any hquid following along the outside of conduit 21 beyond nthis point. Any liquid which reaches projection 43 will drop therefrom into conduit 35 and run back into the absorber. As hole 42 is very small it is usu ally closed with a capillary film of liquid and hence allows no gas to pass therethrough. Thehydrogen gas passes from space 39 through tubes 40 to space 41 and thence upwardly through conduit 25 to the upper part of evaporator 26 Where it again mixes with the ammonia. `Conduit 21 passes in close contact with the inside of the shell of heat exchanger.v 2 4 at the lowest part thereof so that liquid refrigerant flowing out ot' the bottom of the evaporator settles 'around conduit 21 and evaporates in contact there-With whereby the ammonia entering the evaporator is cooled to a great degree.

The water in the `lower part of thevabsorber, known as strong solution, which contains a relatively large percentage of ammonia in solution, passes out of absorber 36 through conduits 48 and 50y to heat exchanger 51. Here it absorbs heat from the water which passes through conduit 53. Heat' ex-y such length'or size or changer 51 may be of of such construction as to` give the desired amount of heat Atransfer. The strong solution passes from heat exchanger 51 through conduit 52to chamber 12 of generator 10. From chamber 12 the strong solution is elevated through thermo-Siphon tube 14 due to heat applied by the gas burner 16 and the arrangement of parts, to the upper part of chamber 11. To effect the thermo-Siphon action, the level v of liquid 1n the absorber is higher than in'chamber 12. In chamber 11,. the ammoniais driven out of solution by the application ofjheat, as previously de- 'i scribed. *The` lwater which contains` butv a relatively small percentage of ammonia in solution, known as the wreak solution passes downwardlyy through ,chamberv 11T (and: through conduit 53 to the top of absorberl 36. 'The weak solution gives up someof its heat tothe strong solution in heatfexchanger 51 and is further cooled by the'clooling water in coil 44. I provide a' coil asthe absorber cooling element in 'preference to t a jacket dueto the smaller crosscoil. l

coil 1s at relasired, the tubing may be fixed in heat transfer relation tothe absorber by casting an aluminum block around the same. The tubing forming the coil or other continuous conduit is preferably made of copper so that there is little or no chance of corrosion. By welding, soldering, or otherwise fusibly connecting the'straight vertical portion of conduit 53 extending upwardly alongside the absorber to the copper coil 44 a simple construction is obtained for precooling the weak absorption liquid passing into the absorber. Conduit 53 is attached to the copper vcoil at each point of contact 58 by soldering or the like. A rod 54 is yinserted in that portion of conduit 53 which-is in heat exchange rela tion with eoil 44. Rod 54 reduces the area of the passageway through 'conduit 53 and etherefore increases the velocity of the weak solution which passes therethrough which results in a better heat transfer from the vweak solutionto the cooling water.

- While I ha've described the preferred apparatus for carrying out the various phases of my invention, I wish it understood that I do not limit myself to the arrangement of apparatus shown and have merely disclosed one form of 'apparatus as sulicient under the requirements of the patent statutes.

Having thus described my invention, what I claim is: I

1. In a refrigerating apparatus, the combination with a device for liquefying a refrigerant, an evaporator and Aa conduit for' conducting the liquefied refrigerant from said deviceto said evaporator of a wick within said conduit. Q

2. In a refrigerating apparatus, the combination with a device for -liquefying a refrigerant, an evaporator, an extended open conduit connecting said vdevice vwith said evaporator for conducting liquid by gravity from said device to said evaporator, of aI metal wick extending within and throughoutsaid conduit. 1.

rator, a heat exchanger.- `a' condenser situ-- ated at a higher level than saidv evaporatornecting said condenser'with the upper part i of sald evaporator and extending through said heat exchanger and a metal wick extending throughout the length of the last mentioned conduit.

5. In an absorption refrigerating appaf ratns, 1n comblnation, a generator, an ab- A sorber, a heat exchanger, means to circulate a gas through said absorber, conduits connecting dilferent spaces`of said he'at'exchanger with said generator, a coil'wound varound said absorber for circulation of cooling liquid, "a conduit connecting the bottom of the absorber with one space of said heat exchanger and a conduit connecting the other space of said heat exchanger with the top of said absorber, the last mentioned conduit extending vertically and contacting with a plurality of convolutions of said coil and a -fused metal connection between vthe upwardly extending conduit and said convolutions.

6. In an absorption refrigerating system,- a condenser, an evaporator, an absorber, a

' vessel situated below said evaporator, meansfor circulating a' gas through said evaporator, vessel and absorber and a conduit lconnecting said condenser with said evaporator, said conduit being, arranged topass through the lowermost portion of said vessel, the arrangement being such that liquid refrigerant 4passing from said evaporator to said vessel evaporates adjacent sald conduit.

7.In an absorption refrigeration system, in combination, an absorber, an evaporator, a heat exchanger situated below said evapolio rator and having a space connected with the lower part of said evaporator adapted toreceive liquid refrigerantrtherefrom, conduitsl for circulating a gas through said absorber,

`'through said heat exchanger, and through said evaporator, a condenser, andl a conduit connecting said condenser with said evaporator passing through said' space at' the bottom thereof and in cont-act with the wall thereof.

8. Absorption refrigerating: apparatus comprising a generator, a condenser, `an

evaporator, and an absorber, the aforemenv tioned parts being interconnected to vform a system wherein a plurality of fluids circulate,

said system including. a horizontal heatl ex-.

changer connected between the absorber and evaporator.v and comprising' a shell, tube heads/within said shell forming end cham-l 4passes and a proj ect-ion on said conduit withy r f absorber comprislng a cylindrical shell,

bers and a central space, tubes fastened into said tube headsand forming passages connecting said end chambers, an opening at the bottom of one of said tube heads, a conduit passing through said opening and along the bottom of said shell, an opening n the bottom of said shell over which said conduit in said opening for preventing passage o liquid along said conduit over said opening.

9. Absorption refrigerating apparatus comprising, in combination, a generator, a condenser, an evaporator, an absorber, means to conduct vapor from said generator to said condenser, means to conduct liquid from said condenser to said evaporator, means 'to conduct gaseous fluid from the evaporator to the absorber, a plurality of members within the absorber for distributing liquid, a continuous conduit on the outside of said absorber, fused metal connection between said continuous conduit and said absorber, said continuous conduit being adapted for the circulation of a cooling medium therethrough and means for circulating absorption liquid between the generator and absorber, the last-mentioned means including a conduit in heat exchange relation with said continuous conduit by fused metal connection.

10. Absorption refrigerating apparatus comprising, in combination, a generator, a

condenser, an evaporator, an'absorber, meansy to conduct vapor from said generator to said condenser, means to conduct liquid from said condenser to said evaporator, means to conduct gaseous fluid from the evaporator to the absorber, a plurality of members Within the absorber for distributing liquid, a continuous conduit on the outside of sald absorber, fused metal connection between said continuous conduit and said absorber, said continuous conduit being adapted for the circulation of a cooling medium therethrough, means for circulating absorption li uid between 'the generator and absorber, ille last-mentioned means including a conduit in heat exchange relation with said continuous conduit by fused metal connection, and a li uid displacing member extending within t e last-mentioned conduit opposite the fused metal connection for increasing the rate of flow of absorption liquid'where the heat transmission.

to the continuous coil takes place.

11. Absorption refrigerating vapparatus comprising', in combination, a generator containing a refrigerant in solution, a condenser connected to the generator for liquefying the refrigerant, an evaporator connected to receive liquid refrigerant from the condenser, an'absorbe'r, means to circulate'an auxiliary gas through the eva orator and absorber'in the presence of whic the refrigerant evaporates, a cooling member for the condenser, a continuous onduit on,r the outside of said absorber, fused metal connect-ion between said continuous coil at a said conduit and said-absorber, said conduit .being adapted vfor the circulation of a cooling medium therethrough, and means to connect said conduit With the cooling member for the condenser.

12. Absorption refrigerating apparatus comprising, in combination," a generator, a condenser, an evaporator, an absorber, `said means to conduct vapor from said generator to said condenser, means to conduct liquid from said condenser to said evaporator, means to conduct gaseous fluid v,from the evaporator to the absorber, a 4plurality of circular disks within the absorber for distributing liquid, a continuous coil conduit wound around the outside of the absorber shell, Y fused metal connect-ion between said conduit and said absorber shell, said conduit being adapted for the circulation of a cooling medium for circulatin absorption liquid between the generator an absorber, the last-mentioned means including a vertically. extending conduit arranged in heat exchange relation with byfused metal connection and a liquid displacing-member extending within. the lastmentioned vertically extending conduit opposite the for increasing the rate oflow of absorption liquid at the places of heat transmission between the vertically extending conduit and the coil'.

13. Absorption refrigerating apparatus comprising, in combination, a genera-tor containing a refrigerant in solution, a condenser therethrough, and means places of fused metal connection plurality of places a connected to the generator for'liquefying the refrigerant, an evaporator connected to receive liquid refrigerant from the condenser, an absorber, said absorber com rising a cylindrical shell, means to circu ate an auxiliary gas through the evaporator andv absorber in the presence erant eva orates, acseries of circular disks in said a sorber, a continuous -copper coil wound around the outside of said absorber adapted' for conduction' of a cooling therethrough, fused metal connection between said coil and said absorber and means of Awhich the refrig-I fluid to circulate absorption liquid between the.

generator and absorber.

Y14. Absorption 'refrigerating lapparatus comprising, in combination, a generator con- .tainlng a refrigerant in solution, a condenser connected to refrigerant,an evaporator connected to receive liquid refrigerant from the condenser, an absorber, said absorber comprising a cylindrical shell, means-to circulate an auxiliary gas` through the evaporator and absorber in the presence of whichLthe iefrig erant vevaporates, a series of circular disks in said absorber, a continuous copper coil wound around the outside of said absorber'.

the generator for liquefying the adapted for conduction of a cooling fluid -therethrough, fused metal connect-ion between said coil and said absorber and'lneans to circulate absorption liquid between the generator and absorber,the last-mentioned meansincluding a conduit arranged in direct heat transmit-ting relation with said coil by fused metal connectionat a plurality of points with said coil.

15. Absorption refrigerating apparatus comprising` a generator comprising a cylindrical shell, a condenser connected to the generator fuor receivingr vapor of refrigerantl therefrom and liquefying the refrigerant, an evaporator connected to receive liquid refrigerant from the condenser, an'absorber, means to circulate an auxiliary gas through the evaporator and absorber in the presence of which the refrigerant evaprates, a flue eX- tending through said generator shell, a partition within said shell forming a main generator and an auxiliary generator',y a thermo-siphon tube connecting said auxiliary generator with said main generator, said auxiliary generator being arranged below .said main generator, a conduit connecting the lower pa-rt of the1 absorber with the auxiliary generatoig'a baffle in the generator flue and means for cooling the absorber and the condenser including a continuous conduit extending around the absorber.y

I n testimony whereof I hereunto aiiix my signature. f

ALVAR LENN ING. 

